1. Field of the Invention
The present invention relates generally to wireless data communication networks and, more specifically, to improving the reliability and efficiency of data transfer for handheld wireless devices that communicate via a wide area network such as the Internet.
2. Description of the Related Art
While in most business organizations an Information Technology (IT) department is charged with procuring, managing, supporting and maintaining desktop, laptop and other computing systems used by individuals within the organization, handheld computing devices that such individuals may use are generally outside the auspices of the IT department and disconnected from the organization's computing infrastructure and the Internet, in effect acting as stand-alone units. To transfer data between two such devices or between such a device and one of the organization's other computing systems, a wireline connection is typically made via serial port cable and/or via telephone land line. Data can be reliably transferred back and forth because the quality and reliability of the connection are relatively high.
Computing devices are increasingly being developed with wireless data communication capability. Such devices can generally be referred to as Handheld Wireless Communicating Devices (HWCDs). HWCDs that go beyond simple data transfer capability have what is generally known as “communicating functionality.” Communicating functionality means that the HWCD possesses some means of transferring data on-the-fly, i.e., while engaged in other computing processes, via a communications network, where the data transfer medium between the handheld device and the edge of the network is not physical, i.e. no cable or telephone lines are directly linked to the device.
Wireless connections are inherently unreliable due to the unpredictable nature of the medium and the limitations of radio transmitters and receivers. Connections are unstable, and can be terminated or “dropped” at any time. Connections are often unavailable altogether. When data needs to be transferred from a HWCD to a remote computer, a wireless connection is made, data is transferred, and the connection is terminated. It is a common occurrence for the connection to drop during transmission because of the instability of wireless infrastructure. In the case of a dropped connection, a new connection must be made, and the entire data set must be transmitted again. This is a problem because of the typically slow speeds of wireless transmission.
It would be desirable to provide a method and system that optimizes data transfer in a wireless communication environment in which intermittent connections can be expected. The present invention addresses this problem and others in the manner described below.